Wordpress Meta未显示在WP REST API查询中

我是WPRESTAPI的新手。只是尝试创建自定义元字段并检索它们。我创建了一个简单的插件，在编辑后的屏幕上注册meta值和metabox，效果很好

<?php
/**
 * @package api_testing
 * @version 1.0.0
 */
/*
Plugin Name: API Testing
Plugin URI: http://example.com/
Description: The beginning of an awesome plugin
Author: Me
Version: 1.0.0
Author URI: http://example.com/
*/

function generate_press_type() {
    $labels = array(
        'name'                  => 'Press Articles',
        'singular_name'         => 'Press',
    );
    $args = array(
        'label'                 => 'Press',
        'labels'                => $labels,
        'supports'              => array( 'title', 'editor', 'custom-fields', 'thumbnail' ),
        'taxonomies'            => array( 'category', 'post_tag' ),
        'hierarchical'          => false,
        'public'                => true,
        'capability_type'       => 'post',
        'show_in_rest'          => true,
        'rest_base'             => 'press-articles',
        'rewrite'               => true,
        'rewrite_slug'          => '',        
    );
    register_post_type( 'press_article', $args );
    
}
add_action( 'init', 'generate_press_type', 0 );
function create_meta() {
    $args1 = array(
        'type'      => 'string', // Validate and sanitize the meta value as a string. 
            // In 4.7 one of 'string', 'boolean', 'integer', 'number' must be used as 'type'. 
        'description'    => 'A meta key associated with a string meta value.', // Shown in the schema for the meta key.
        'single'        => true, // Return a single value of the type. Default: false.
        'show_in_rest'    => true, // Show in the WP REST API response. Default: false.
    );
     
    register_meta( 'post', 'wporg_field', $args1 );
}


function wporg_add_custom_box() {
    $screens = [ 'post', 'wporg_cpt' ];
    foreach ( $screens as $screen ) {
        add_meta_box(
            'wporg_box_id',                 // Unique ID
            'Custom Meta Box Title',      // Box title
            'wporg_custom_box_html',  // Content callback, must be of type callable
            $screen                            // Post type
        );
    }
}
add_action( 'add_meta_boxes', 'wporg_add_custom_box' );

function wporg_custom_box_html( $post ) {
    $value = get_post_meta( $post->ID, '_wporg_meta_key', true );
    ?>
    <label for="wporg_field">Description for this field</label>
    <select name="wporg_field" id="wporg_field" class="postbox">
        <option value="">Select something...</option>
        <option value="something" <?php selected( $value, 'something' ); ?>>Something</option>
        <option value="else" <?php selected( $value, 'else' ); ?>>Else</option>
    </select>
    <?php
}

function wporg_save_postdata( $post_id ) {
    if ( array_key_exists( 'wporg_field', $_POST ) ) {
        update_post_meta(
            $post_id,
            '_wporg_meta_key',
            $_POST['wporg_field']
        );
    }
}
add_action( 'save_post', 'wporg_save_postdata' );

此字段的说明
选择一些。。。
>否则
{
    "id": 1172,
    "date": "2019-09-20T17:50:23",
    "date_gmt": "2019-09-21T00:50:23",
    "guid": {
      "rendered": "http://example.com/?p=1172"
    },
    "modified": "2020-11-08T08:56:43",
    "slug": "review-ensemble-fanaas-self-titled-debut-record",
    "status": "publish",
    "type": "post",
    "link": "http://example.com/review-ensemble-fanaas-self-titled-debut-record/",
    "title": {
      "rendered": "Review: Ensemble Fanaa’s Self-titled Debut Record"
    },
    "content": {
      "rendered": "<blockquote class=\"wp-embedded-content\" data-secret=\"LyNp7sCidr\"><p><a href=\"https://www.jazzrightnow.com/review-ensemble-fanaas-self-titled-debut-record/\">Review: Ensemble Fanaa&#8217;s Self-titled Debut Record</a></p></blockquote>\n<p><iframe class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; clip: rect(1px, 1px, 1px, 1px);\" title=\"&#8220;Review: Ensemble Fanaa&#8217;s Self-titled Debut Record&#8221; &#8212; Jazz Right Now\" src=\"https://www.jazzrightnow.com/review-ensemble-fanaas-self-titled-debut-record/embed/#?secret=LyNp7sCidr\" data-secret=\"LyNp7sCidr\" width=\"600\" height=\"338\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"></iframe></p>\n",
      "protected": false
    },
    "excerpt": {
      "rendered": "<p>Review: Ensemble Fanaa&#8217;s Self-titled Debut Record</p>\n",
      "protected": false
    },
    "meta": [], <------
    "categories": [
      12
    ],
    "tags": [],
  }